Such a device is while known as bottle-handling machine, for example composed of a filling machine and a labelling machine. In such case, the bottles are supplied to each of these machines in a lined-up fashion (a stream), and subsequently discharged in the same or a different lined-up fashion. The connection between the two successive machines consists of the aforementioned two parallel classifying worms which are disposed at some distance from one another and which also partially overlap one another. Such a connecting device is especially important when handling non-round objects (bottles or cans) which are not capable of being temporarily stored in a buffer supply and subsequently withdrawn therefrom.
When there occurs a disturbance somewhere, the installation must be stopped. If the installation comprises a labeling machine, it must be unloaded, however, because in the event of a long stoppage, the mass of glue applied for the labeling operation will dry and harden. In such case, it is known in practice to uncouple the labeling machine from the other machine and to manually remove the bottles present in the (helical) grooves of the first classifying worm. Thereupon, the labeling machine is engaged at a low or creep-speed by means of its own drive until the bottles in the path of travel from the overlap have all been removed. As soon as the disturbance has been eliminatedd, the installation is again operated at normal speed so as to resynchronize the machines. Thereupon, the bottles initially taken out of the first worm must be placed back immediately. This is not only a time consuming operation but also hampers the manual placing and removing of bottles, because it is necessary to first remove the safety protection means.